Good News, Bad News for Bay Area Quakes

Good news: Compared to the previous assessment issued in 2008, UCERF2, the estimated rate of earthquakes around magnitude 6.7 — the size of the destructive 1994 Northridge earthquake — has gone down by about 30 percent. The expected frequency of such events statewide has dropped from an average of one per 4.8 years to about one per 6.3 years.

Bad news: However, in the new study, the estimate for the likelihood that California will experience a magnitude 8 or larger earthquake in the next 30 years has increased from about 4.7% to about 7.0%.